发明名称 PUSHHBUTTON DIAL SIGNAL SYSTEM
摘要 PURPOSE:To secure an assured prevention for the malfunction of the PB signal receiver caused by the aural false signal, by providing the current limiting element and receiving the multi-frequency dial signal through detection of the error of the DC loop resistance.
申请公布号 JPS5437409(A) 申请公布日期 1979.03.19
申请号 JP19770102615 申请日期 1977.08.29
申请人 IWATSU ELECTRIC CO LTD 发明人 FUJIMURA TADAO
分类号 H04Q1/45;H04Q1/453 主分类号 H04Q1/45
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